I’ve got no answer for this question. I did a brief search for studies on the subject, but they seemed inconclusive (i.e., they were over my head).
The subject is the expression of emotion via voice, more specifically the expression of a general state of, if not happiness, then at least contentment. It comes to mind when listening to old-time radio dramas. We, the listener, must rely on our imagination to picture what is happening, but that’s a bit simplistic. We’re relying on the music, the dialogue, the sound effects, everything that enters our imagination.
Gunsmoke was arguably the greatest of all radio dramas. Certainly it was the best Western. I’m speaking only of the radio version, because I’m concerned with the use of the voice to suggest emotion, and the television version adds visual information that taints what I’m trying to figure out.
One reason Gunsmoke was a great show was that William Conrad played the lead, Marshal Matt Dillon. I’m tossing out a lot of superlatives, here, but Conrad was one of the greatest of all radio actors. He wasn’t asked to play Dillon on TV ... as became clear when he later starred in shows like Cannon and Jake and the Fatman, Conrad didn’t exactly look like an imposing lawman. (James Arness, 6’7” tall, did look imposing, and he made a fine Marshal.) But as a voice actor, Conrad was at the top of many people’s lists. (He served as the narrator for countless TV series over the years.)
Conrad could sound like a serious badass. When Marshal Dillon got pissed, Conrad’s acting anger grabbed the listener through the radio speaker. He was also excellent at conveying the wary life of a lawman, as he would say at the beginning of each episode, “I'm that man, Matt Dillon, United States Marshal -- the first man they look for and the last they want to meet. It's a chancy job, and it makes a man watchful . . . and a little lonely.”
But even Matt Dillon would occasionally find a brief moment or two to relax, even to enjoy life for a bit. Usually, this came when he greeted Miss Kitty, the “saloon hostess” in Dodge City. Conrad’s voice would convey that happiness.
And that’s my question. How the hell did Conrad do it?
I could ask this about any voice actor, of course. I don’t have any problem understanding the way an actor could convey anger, or fear, or similar emotions. But somehow, when Matt said something as simple as “Hello, Kitty”, you know he’s smiling. And I don’t know how we can tell.
Here’s an episode from 1955. If you just want to hear an example of the above, listen to the first couple of minutes, through the conversation between Matt and Kitty. The way Conrad slides a chuckle into his line reading is easy enough to grasp. I’m not talking about that. I’m talking about the way he already sounds happy when he says “Hello, Kitty”.